systems and methods for performing a visual field test of a patient are described. One example method for performing the visual field test of the patient using a visual field testing device having a refractive correction element, a patient support, and a motor operably attached to one of the refractive correction element or the patient support includes positioning the patient's head relative to the device using the patient support. An image showing the position of the eye relative to the refractive correction element is collected. The relative displacement of the eye with respect to the refractive correction element is determined based on the collected image. The motor is actuated in a manner to reduce the determined displacement. A series of test stimuli is displayed to the patient's eye and responses to the test stimuli are received from the patient. The responses are analyzed to make an assessment of the patient's visual field.
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10. A visual field testing system for performing a visual field test of a patient, said system comprises:
a patient support for positioning the patient's head relative to the system;
a refractive correction element operably attached to said system for correcting the refractive error of the patient;
a motor operably attached to one of the refractive correction element or the patient support for changing the location of the refractive correction element with respect to the patient support;
a camera for capturing an image of the patient's eye, said image displaying the position of the patient's eye relative to the refractive correction element;
a processor for determining the relative displacement of the patient's eye with respect to the refractive correction element based on the captured image
and wherein the relative displacement is determined by segmenting the image to locate the refractive correction element's perimeter and the patient's pupil, determining a center of the refractive correction element and a center of the patient's pupil, and calculating the separation distance between the center of the refractive correction element and the center of the patient's pupil in the plane of the image, said processor for actuating the motor in a manner to reduce the determined displacement;
a display for displaying a series of test stimuli to the eye of the patient; and
a response mechanism for receiving patient responses to the test stimuli.
1. A method for performing a visual field test of a patient using a visual field testing device having a refractive correction element, a patient support, and a motor operably attached to one of the refractive correction element or the patient support for changing the location of the refractive correction element relative to the patient support, said method comprising:
positioning the patient's head relative to the visual field testing device using the patient support;
collecting an image of the patient's eye, said image displaying the position of the eye relative to the refractive correction element;
determining the relative displacement of the patient's eye with respect to the refractive correction element based on the collected image, wherein the step of determining the relative displacement includes;
segmenting the image to locate the refractive correction element's perimeter and the patient's pupil;
determining a center of the refractive correction element and a center of the patient's pupil; and
calculating the separation distance between the center of the refractive correction element and the center of the patient's pupil in the plane of the image;
actuating the motor in a manner to reduce the determined displacement;
displaying a series of test stimuli to the eye of the patient;
receiving responses to the test stimuli from the patient;
analyzing the received responses to make an assessment of the patient's visual field; and
displaying or storing the assessment or a further analysis thereof.
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This application claims priority to U.S. Provisional Application Ser. No. 62/301,229, filed Feb. 29, 2016, the contents of which are hereby incorporated by reference.
The present application relates to the field of aligning a patient's eye relative to a refractive correction element. In particular, it discloses an approach for automatically positioning the patient's eye relative to the center of the refractive correction element. This is particularly useful for visual field testing devices that use liquid trial lenses or conventional ophthalmic trial lenses or other means of refraction correction.
A lens is often used for refractive correction during a course of perimetry or other types of visual field testing of a patient. One example of refractive correction is a liquid trial lens (see for example U.S. Pat. No. 8,668,338, the contents of which are hereby incorporated by reference), which may be more sensitive to patient eye alignment than other trial lenses. Prior to beginning a perimetry test, a technician operating the perimeter typically tries to center a patient's eye at or near the z-axis (the axis of symmetry) of the perimeter's bowl. Live image(s) or video of the eye, captured using the instrument's camera, are displayed to the technician for patient alignment or test verification purposes. The technician sets an initial patient pupil position by adjusting the chin rest until the eye is determined to be centered in the displayed eye video. This initial position may or may not be centered on the refractive correction lens in use. Further, patients move around during the course of the testing. Due to these factors, the patient's eye is often misaligned with the correction lens, or becomes misaligned during the course of testing. This misalignment can result in 1) poor gaze monitor performance, 2) trial lens rim artifacts in the visual field report, and 3) degraded retinal sensitivity measurements due to stimulus blur induced by such decentration of the eye relative to the lens center.
Some perimeters use a set of fixed focus trial lenses for refraction correction. These lenses typically may not be as sensitive to decentration as is a liquid trial lens with regard to successful gaze monitor performance, but still can generate trial lens artifacts if the eye is not accurately aligned to the center of the lens. Thus, there is a need for an approach that can correctly position or align a patient's eye to the center of the refractive correction lens.
According to one aspect of the subject matter described in the present application, a method for performing a visual field test of a patient using a visual field testing device having a refractive correction element, a patient support, and a motor operably attached to one of the refractive correction element or the patient support for changing the location of the refractive correction element relative to the patient support includes positioning the patient's head relative to the visual field testing device using the patient support; collecting an image of the patient's eye, said image displaying the position of the eye relative to the refractive correction element; determining the relative displacement of the patient's eye with respect to the refractive correction element based on the collected image; actuating the motor in a manner to reduce the determined displacement; displaying a series of test stimuli to the eye of the patient; receiving responses to the test stimuli from the patient; analyzing the received responses to make an assessment of the patient's visual field; and displaying or storing the assessment or a further analysis thereof.
According to another aspect of the subject matter described in the present application, a visual field system for performing a visual field test of a patient includes a patient support for positioning the patient's head relative to the system; a refractive correction element operably attached to said system for correcting the refractive error of the patient; a motor operably attached to one of the refractive correction element or the patient support for changing the location of the refractive correction element with respect to the patient support; a camera for capturing an image of the patient's eye, said image displaying the position of the patient's eye relative to the refractive correction element; a processor for determining the relative displacement of the patient's eye with respect to the refractive correction element based on the captured image and actuating the motor in a manner to reduce the determined displacement; a display for displaying a series of test stimuli to the eye of the patient; and a response mechanism for receiving patient responses to the test stimuli.
The visual testing system of the present application automatically aligns the patient eye to the center of the refractive correction element (e.g., liquid trial lens) rather than using an initial position established by the attending technician. It does so by 1) finding the perimeter of the element (e.g., clear lens aperture), 2) calculating the location of the center of the element, and 3) locating the center of the eye's pupil. In a preferred embodiment, the system drives the x- and y-axis chin rest motors, moving the patient to minimize the separation distance between the refractive correction element's center and the patient's pupil center. The separation distance is measured in the plane of images provided by the system's camera. In this way, the system centers the eye relative to the refractive correction element and compensates for small patient head movements.
The automatic alignment of the refractive correction element with the patient's eye discussed herein is advantageous in a number of respects. For instance, the system continually (i.e. frequently, and during the entire course of a perimetry test) re-centers the patient's eye relative to the refractive correction element. A properly centered eye can minimize 1) magnitude of errors in patient gaze estimation, 2) lens rim artifacts, and 3) likelihood of retinal sensitivity errors due to stimulus blur.
The features and/or advantages described herein are not all-inclusive and many additional features and/or advantages will be apparent to one of ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and not to limit the scope of the inventive subject matter.
All patent and non-patent references cited within this specification are herein incorporated by reference in their entirety to the same extent as if the disclosure of each individual patent and non-patient reference was specifically and individually indicated to be incorporated by reference in its entirely.
The automated alignment approach described herein could be used in conjunction with any type of visual field tester or perimeter containing a refractive correction element 109, such as a liquid trial lens. One such system 100 is illustrated in
The camera 108 can record and store one or more images of the eye during each stimulus presentation. This may lead to the collection of anywhere from tens to hundreds of images per visual field test, depending on the testing conditions. Alternatively, the camera 108 may record and store a full length movie during the test and provide time stamps when each stimulus is presented. Additionally, images may also be collected between stimulus presentations to provide details on the subject's overall attention throughout the test's duration.
In a preferred embodiment of the present invention, the refractive correction element 109 comprises a tunable optical element such as a liquid trial lens (see for example U.S. Pat. No. 8,668,338, the contents of which are hereby incorporated by reference), which is utilized to provide a variable refractive correction of the subject 101. However, it should be noted that the present invention is not limited to using the liquid trial lens for refractive correction and other types of adjustable lenses and conventional/standard trial lenses known in the art can also be used with the present invention. An example liquid trial lens is depicted in
One of the previous approaches for centering or aligning a patient's eye with a refractive correction lens involved a technician setting an initial pupil position, which may or may not be centered on the refractive correction lens as discussed elsewhere herein. Example of such a scenario is depicted via images
An embodiment of the present invention includes an instrument control algorithm, which may be software, code, and/or a routine that uses existing hardware signals and a motorized positioning system to automatically position the patient's eye at the center of the refractive correction lens placed in front of the eye. The algorithm can be used with any type of visual field tester or perimeter (e.g., the visual field test system shown in
In step 304, an image is collected showing the patient's eye and a small area it including the refractive correction lens 109 (e.g., see images displayed in
Once the displacement is reduced, a visual field test is initiated to make an assessment of the patient's visual field (step 308), and the results of such assessment is displayed or stored for future access and/or retrieval (step 310). As discussed in
In some implementations, the steps of
In step 402, the instrument control algorithm segments the image collected in step 304 (
In some embodiments, the step 307 of
In some embodiments, the instrument control algorithm may pause perimetry test execution while chin rest, forehead, and/or refractive correction element motor movements are under way if such movements would disrupt test execution. If reduction of the separation distance requires a large movement that would result in an unacceptably long pause, the algorithm may split total movement into segments. One segment will be executed per stimulus presentation. The algorithm will re-assess required movement for each stimulus presentation, regardless of uncompleted segments.
Example Computer System
The processing unit or processor 105 that has been discussed herein in reference to
The components 602, 604, 606, 608, and 610 are communicatively coupled via a communication or system bus 612. The bus 612 can include a conventional communication bus for transferring data between components of a computing device or between computing devices. It should be understood that the computing system 600 described herein is not limited to these components and may include various operating systems, sensors, video processing components, input/output ports, user interface devices (e.g., keyboards, pointing devices, displays, microphones, sound reproduction systems, and/or touch screens), additional processors, and other physical configurations.
The processor(s) 602 may execute various hardware and/or software logic, such as software instructions, by performing various input/output, logical, and/or mathematical operations. The processor(s) 602 may have various computing architectures to process data signals including, for example, a complex instruction set computer (CISC) architecture, a reduced instruction set computer (RISC) architecture, and/or architecture implementing a combination of instruction sets. The processor(s) 602 may be physical and/or virtual, and may include a single core or plurality of processing units and/or cores. In some embodiments, the processor(s) 602 may be capable of generating and providing electronic display signals to a display device, such as the display 606, supporting the display of images, capturing and transmitting images, performing complex tasks including various types of feature extraction and sampling, etc. In some embodiments, the processor(s) 602 may be coupled to the memory(ies) 604 via a data/communication bus to access data and instructions therefrom and store data therein. The bus 612 may couple the processor(s) 602 to the other components of the computer system 600, for example, the memory(ies) 604 or the data store 610.
The memory(ies) 604 may store instructions and/or data that may be executed by the processor(s) 602. In the depicted embodiment, the memory(ies) 604 stores at least the instrument control algorithm 605, which may include software, code, logic, or routines, executable by the processor(s) 602, for automatically aligning a patient's eye relative to a refractive correction element as discussed elsewhere herein. For instance, the instrument control algorithm 605 may perform the step 306 (including steps 402-410) and step 307 depicted in
The display 606 represents any device equipped to display electronic images and data as described herein. The display 606 may be any of a conventional display device, monitor or screen, such as an organic light-emitting diode (OLED) display, a liquid crystal display (LCD). In some embodiments, the display 606 is a touch-screen display capable of receiving input from one or more fingers of a user. For example, the device 606 may be a capacitive touch-screen display capable of detecting and interpreting multiple points of contact with the display surface.
The input device(s) 608 are any devices for inputting data on the computer system 600. In some embodiments, an input device is a touch-screen display capable of receiving input from one or more fingers of the user. The functionality of the input device(s) 608 and the display 606 may be integrated, and a user of the computer system 600 may interact with the system by contacting a surface of the display 606 using one or more fingers. In other embodiments, an input device is a separate peripheral device or combination of devices. For example, the input device(s) 608 may include a keyboard (e.g., a QWERTY keyboard) and a pointing device (e.g., a mouse or touchpad). The input device(s) 608 may also include a microphone, a web camera, or other similar audio or video capture devices.
The data store 610 can be an information source capable of storing and providing access to data.
In the depicted embodiment, the data store 610 is coupled for communication with the components 602, 604, 606, and 608 of the computer system 600 via the bus 612, and coupled, via the processor(s) 602, for communication with the instrument control algorithm 605. In some embodiments, the instrument control algorithm 605 is configured to manipulate, i.e., store, query, update, and/or delete, data stored in the data store 610 using programmatic operations.
In the above description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the specification. It should be apparent, however, that the subject matter of the present application can be practiced without these specific details. It should be understood that the reference in the specification to “one embodiment”, “some embodiments”, or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the description. The appearances of the phrase “in one embodiment” or “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment(s).
The foregoing description of the embodiments of the present subject matter has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present embodiment of subject matter to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the present embodiment of subject matter be limited not by this detailed description, but rather by the claims of this application. As will be understood by those familiar with the art, the present subject matter may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Furthermore, it should be understood that the modules, routines, features, attributes, methodologies and other aspects of the present subject matter can be implemented using hardware, firmware, software, or any combination of the three.
Patella, Vincent Michael, Stevens, Jeffrey Donald
Patent | Priority | Assignee | Title |
10642355, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field display, adjusted pixel rendering method therefor, and vision correction system and method using same |
10699373, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field display, adjusted pixel rendering method therefor, and vision correction system and method using same |
10761604, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field vision testing device, adjusted pixel rendering method therefor, and vision testing system and method using same |
10860099, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field display, adjusted pixel rendering method therefor, and adjusted vision perception system and method using same addressing astigmatism or similar conditions |
10884495, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field display, adjusted pixel rendering method therefor, and vision correction system and method using same |
10936064, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field display, adjusted pixel rendering method therefor, and adjusted vision perception system and method using same addressing astigmatism or similar conditions |
11262901, | Aug 25 2015 | EVOLUTION OPTIKS LIMITED | Electronic device, method and computer-readable medium for a user having reduced visual acuity |
11287883, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field device, pixel rendering method therefor, and adjusted vision perception system and method using same |
11327563, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field vision-based testing device, adjusted pixel rendering method therefor, and online vision-based testing management system and method using same |
11353699, | Mar 09 2018 | EVOLUTION OPTIKS LIMITED | Vision correction system and method, light field display and light field shaping layer and alignment therefor |
11487361, | Nov 01 2019 | EVOLUTION OPTIKS LIMITED | Light field device and vision testing system using same |
11500460, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field device, optical aberration compensation or simulation rendering |
11500461, | Nov 01 2019 | EVOLUTION OPTIKS LIMITED | Light field vision-based testing device, system and method |
11619995, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field vision-based testing device, adjusted pixel rendering method therefor, and online vision-based testing management system and method using same |
11635617, | Apr 23 2019 | EVOLUTION OPTIKS LIMITED | Digital display device comprising a complementary light field display or display portion, and vision correction system and method using same |
11693239, | Mar 09 2018 | EVOLUTION OPTIKS LIMITED | Vision correction system and method, light field display and light field shaping layer and alignment therefor |
11726563, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field device, pixel rendering method therefor, and adjusted vision perception system and method using same |
11762463, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field device, optical aberration compensation or simulation rendering method and vision testing system using same |
11789531, | Aug 22 2010 | EVOLUTION OPTIKS LIMITED | Light field vision-based testing device, system and method |
11823598, | Nov 01 2019 | EVOLUTION OPTIKS LIMITED | Light field device, variable perception pixel rendering method therefor, and variable perception system and method using same |
11841988, | Oct 22 2018 | EVOLUTION OPTIKS LIMITED | Light field vision-based testing device, adjusted pixel rendering method therefor, and online vision-based testing management system and method using same |
11899205, | Apr 23 2019 | EVOLUTION OPTIKS LIMITED | Digital display device comprising a complementary light field display or display portion, and vision correction system and method using same |
11902498, | Aug 26 2019 | EVOLUTION OPTIKS LIMITED | Binocular light field display, adjusted pixel rendering method therefor, and vision correction system and method using same |
Patent | Priority | Assignee | Title |
3718386, | |||
5220361, | Jun 05 1991 | Allergan Humphrey | Gaze tracking for field analyzer |
5381195, | Mar 22 1993 | Method and apparatus for testing a subject's perception of visual stimuli | |
5491757, | Dec 22 1993 | CARL ZEISS, INC | Field tester gaze tracking using content addressable memories to improve image data analysis speed |
5598235, | Mar 22 1994 | Method and an apparatus for testing a subject's response to visual stimuli | |
7401921, | May 12 2004 | CARL ZEISS MEDITEC, INC | Motorized patient support for eye examination or treatment |
8132916, | Dec 12 2008 | CARL ZEISS MEDITEC, INC | High precision contrast ratio display for visual stimulus |
8668338, | Mar 17 2011 | CARL ZEISS MEDITEC, INC | Systems and methods for refractive correction in visual field testing |
8684529, | Apr 28 2011 | CARL ZEISS MEDITEC, INC | Systems and methods for improved visual field testing |
9179833, | Feb 28 2013 | CARL ZEISS MEDITEC, INC | Systems and methods for improved ease and accuracy of gaze tracking |
20110299034, | |||
20120287401, | |||
20130044290, | |||
20130070204, |
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